"This is really bad. It is starting to fly like a bamboo ship," said the pilot, according to comments captured on the 737's cockpit voice recorder.
Indonesia's National Transportation Safety Committee said on Tuesday that 154 recurring defects in the aircraft's navigation system were reported in the months leading up to the disaster.
Low-cost carrier Adam Air failed to properly address those reports.
Structural failure
Tatang Kurniadi, transportation safety committee chairman, said flight recorder data indicated a significant structural failure before the crash.
"The pilots' failure was the last stage in the process after the plane entered a critical altitude," he said.
Transport authorities imposed a flying ban on Adam Air this month over safety concerns. The ban will be evaluated in three months.
All of the airline's Boeing 737-300 aircraft were grounded temporarily last year after the fuselage of one aircraft cracked on landing.
Batam incident
Earlier this month, an Adam Air Boeing 737-400 with 175 people on board skidded off the runway in bad weather in Batam.
The non-fatal incident prompted a private consortium led by PT Bhakti Investama to unload its 50 per cent stake in the airline, citing dissatisfaction with its safety performance.
Indonesia's airline industry has boomed in the past decade as new budget carriers have offered passengers a wider choice of routes across the sprawling archipelago.
A series of airline disasters in Indonesia during recent years, however, has raised concerns about safety standards and prompted the European Union to ban all Indonesian airlines from its airspace.